Abstract: Described herein are labeled proteins and methods of use thereof for identifying the position of multiple disulfide bridges present in the peptide. The methods combine the use of diselenide bridges and NMR-based mapping of the disulfide bridges. Also described herein are labeled proteins described above that contain fluorous bridges and spacers that facilitate oxidative folding of the protein. The resulting biorthogonal oxidation strategy for studying disulfide-rich peptides both improves oxidative folding and provides simultaneous determination of the disulfide crosslink connectivity in the peptide. The methods permit routine and facile production of disulfide-rich peptides.